The first Columbus voyage will be disappointing in not finding gold.
But land and freshwater should be found.
Columbus will no doubt say that these wild islands should be used as bases to keep exploring just a little further, where surely, the orient must be.
He should at least have some novel animals or remains of animals to show when he gets back to Spain.
He and his crew will find these,
The giant ground sloth - on the islands. No way is one of those going to be dragged on a ship and kept alive for the trip back to Spain. Even a full corpse if preserved or stuffed would take up too much cargo space and be too heavy, but the royals are going to get one or more hell of a giant "bearskin rug" made out of these beasts.
Unless there's nobody with taxidermy skills, there should be some examples of some large, colorful birds and monkey, unknown in Europe, like the three foot owl:
giant barn owl
. Caribbean version of giant Haast eagle
. Terror bird and Ibis
. Flightless crane
https://imgur.com/13zzCKo
And if there's no competent taxidermists, they'll at least get feathers and beaks or heads and talons.